Energy companies, from modest ventures to global giants, are anxiously awaiting a decision by the Public Utility Commission that likely will come next month: The amount of wind transmission to build in Texas.
With wind farms expanding from West Texas to the Panhandle, energy companies and regulators agree there should be more transmission to get wind power from West Texas to the state’s biggest cities.
But how much transmission should be added is matter of heated debate.
T. Boone Pickens’ Mesa Power, Shell’s wind subsidiary and Spanish-based giant Iberdrola are among the companies supporting the most aggressive plan of five the commission is considering.
By contrast, San Antonio’s city-owned utility, CPS Energy, supports a more modest expansion. The utility has taken heat from environmentalists for not backing the most ambitious expansion plan.
CPS says it would like to see transmission phased in so that wind can be meshed with the grid to maintain reliability. And the plan can be expanded.
The PUC likely will take up wind transmission at its July 17 meeting, but isn’t expected to make a decision until its Aug. 14 meeting, a spokesman said. The five plans range from adding transmission to handle 12,053 megawatts of installed wind generation at a cost of $2.95 billion to a plan to build transmission to handle almost 25,000 megawatts at a cost of almost $6.4 billion.
The latter plan would be enough transmission to power 2.4 million to 4.9 million homes in Texas on a hot day at a single moment of peak demand. (A megawatt can power about 200 homes in hot weather when air conditioners are running.)
CPS supports a proposal that would add transmission to handle 12,053 megawatts at a cost of about $3.8 billion and would be expandable.
The scenario CPS supports is not a modest step, deputy general manager Steve Bartley said. “It would support more than 12,000 megawatts of wind. That’s more than double what we have today.”
The plan is “a first step,” Bartley said. “We believe that we need to do transmission in phases so that we can assess the reliability as we ratchet wind up.”
CPS isn’t anti-wind, he said. It is No. 1 among U.S. municipal utilities in the amount of wind power it buys, and it will be the first utility to buy wind from the Texas coast, starting later this year.
“We think CPS is taking a very narrow view,” said Luke Metzger, director of Environment Texas, an environmental advocacy organization. “It’s unfortunate that CPS is making public proclamations about support for renewables, but behind closed doors they’re resisting policies that we need to get there.”
The PUC also has questioned CPS’ position. At a June 11 hearing, PUC Chairman Barry Smitherman told a CPS lawyer, “I hear this cautionary note coming from you. We want wind, we want to be green, (but) we want you to go slow. You’re asking us to walk a very fine line here.”
Smitherman said he fears that adopting the plan CPS supports would mean wind developers will decide to take their capital “and play somewhere else.”
But CPS’ concerns about integrating wind with the Texas grid are real, one expert said. The reliability of any electric grid is a concern when large amounts of wind generation are added, said Peter Hartley, professor of energy economics at Rice University in Houston.
“The fluctuations from wind can be very sudden, so most power systems are reluctant to have too much wind for that reason,” he said. “If you have a lot of wind power and the wind drops suddenly, you can have voltage drops and brownouts or blackouts.”
Wind was a factor in a grid emergency on Feb. 26, when a cold front blew through West Texas. Wind-generated power ginned up, then fell off over three hours. Meanwhile, more customers than normal flipped switches at home. The grid faced a situation where more power was being used than generated. “That’s dangerous territory,” said Dottie Roark, spokeswoman for grid operator ERCOT, the Electric Reliability Council of Texas.
The imbalance caused ERCOT to take special measures, curtailing power to customers who have agreed their juice can be cut for a time, Roark said.
“We weren’t in danger of rolling blackouts” on Feb. 26, Roark said. “But the system operators will also be quick to tell you that there is an inherent challenge to incorporating large amounts of wind because it’s an intermittent resource. It can’t be controlled.”
Cost of wind transmission, too, is an issue.
“To build transmission lines is very expensive,” Rice’s Hartley said. Transmission lines must have a lot of capacity to get the power where it’s needed, but with wind power “you’re not using the lines very often” because the wind doesn’t always blow.
Also, when there’s peak demand for power, there may be little wind. “That means you have to have backup generation, and that also makes wind very expensive,” Hartley said. “You could just build the backup by itself without the wind, and that’s going to be cheaper.”
But the potential complications haven’t discouraged some big energy companies from backing the most ambitious transmission plans.
Without a major expansion of power lines, some companies hint that they could abandon plans to build or power generated by wind farms could be constrained.
Shell WindEnergy supports the most aggressive plan, as does Spain’s Iberdrola Renewables and Babcock and Brown Renewable Holdings, part of an Australian energy company.
“What’s right,” Babcock and Brown wrote in a brief, “is not the adoption of timid half-measures.”
By Vicki Vaughan
3 July 2008
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